A source familiar with the Harbour Energy approach said talks had slowed since last year.

“There’s little activity at the moment,” he said

While Harbour Energy chief executive Linda Cook was reportedly in Australia late last year, it is not known whether she has returned since that time.

The two groups already have a link, with Hock Goh serving as a director on the boards of both Santos and Harbour Energy.

A Santos spokeswoman confirmed a potential conflict of interest for Mr Goh at the time.

"Mr Goh did not participate in any deliberations relating to Harbour Energy's confidential, non-binding, conditional and indicative proposal in August (2017)," she told Fairfax Media.

"Hock Goh will take a leave of absence from the Santos board until Harbour Energy's position is definitively established."

Mr Goh is still on leave.

Yet, this has not taken it off the table for other prospective buyers.

“We still see Santos as a takeover target for any player looking to make their way into LNG or diversify in the space,” Mr Kavonic told Fairfax Media.

He said it could be a target of interest for large national oil companies globally or emerging players who have an interest in LNG in Australia.

“There aren’t many sub-$10 billion companies with assets like these in the world,” he said.

Mr Gallagher told Fairfax Media there was nothing to say on a potential takeover.

“We said repeatedly if there were any further developments we would keep the market updated; as there have been no updates it means there have been no developments on that front,” he said.

“If you’ve got good, strong core assets and deliver at competitive costs then it's not surprising you would see interest, and we take it as a compliment. Our focus remains on running the business well.”

Santos opened trading at $5.30, up 2.3 per cent from the previous day’s close, however, it quickly fell to a midday trading point of $5.26.